/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSG_GL
#define OSG_GL 1

#include <osg/Config>
#include <osg/Export>

#ifndef WIN32

    // Required for compatibility with glext.h sytle function definitions of 
    // OpenGL extensions, such as in src/osg/Point.cpp.
    #ifndef APIENTRY
        #define APIENTRY
    #endif

#else // WIN32

    #if defined(__CYGWIN__) || defined(__MINGW32__)

        #ifndef APIENTRY
            #define GLUT_APIENTRY_DEFINED
            #define APIENTRY    __stdcall
        #endif
               // XXX This is from Win32's <windef.h> 
        #ifndef CALLBACK
            #define CALLBACK __stdcall
        #endif

    #else // ! __CYGWIN__

        // Under Windows avoid including <windows.h>
        // to avoid name space pollution, but Win32's <GL/gl.h> 
        // needs APIENTRY and WINGDIAPI defined properly. 
           // XXX This is from Win32's <windef.h> 
        #ifndef APIENTRY
            #define GLUT_APIENTRY_DEFINED
            #if (_MSC_VER >= 800) || defined(_STDCALL_SUPPORTED)
                #define WINAPI        __stdcall
                #define APIENTRY    WINAPI
            #else
                #define APIENTRY
            #endif
        #endif

         // XXX This is from Win32's <windef.h> 
        #ifndef CALLBACK
            #if (_MSC_VER >= 800) || defined(_STDCALL_SUPPORTED)
                #define CALLBACK __stdcall
            #else
                #define CALLBACK
            #endif
        #endif

    #endif // __CYGWIN__

           // XXX This is from Win32's <wingdi.h> and <winnt.h> 
    #ifndef WINGDIAPI
        #define GLUT_WINGDIAPI_DEFINED
        #define DECLSPEC_IMPORT    __declspec(dllimport)
        #define WINGDIAPI DECLSPEC_IMPORT
    #endif
           // XXX This is from Win32's <ctype.h>

    #if !defined(_WCHAR_T_DEFINED) && !(defined(__GNUC__)&&((__GNUC__ == 3)||(__GNUC__ == 4)))
        typedef unsigned short wchar_t;
        #define _WCHAR_T_DEFINED
    #endif

#endif // WIN32

#if defined(OSG_GLES1_AVAILABLE)

    #include <GLES/gl.h>

#elif defined(OSG_GLES2_AVAILABLE)

    #include <GLES2/gl2.h>

#elif defined(OSG_GL3_AVAILABLE)

    #define GL3_PROTOTYPES 1
    #include <GL3/gl3.h>

#else

    #ifndef __gl_h_
        #ifdef __APPLE__
            #include <OpenGL/gl.h>
        #else
            #include <GL/gl.h>
        #endif
    #endif

#endif


#ifdef OSG_GL_MATRICES_AVAILABLE

    inline void glLoadMatrix(const float* mat) { glLoadMatrixf(static_cast<const GLfloat*>(mat)); }
    inline void glMultMatrix(const float* mat) { glMultMatrixf(static_cast<const GLfloat*>(mat)); }

    #ifdef OSG_GLES1_AVAILABLE
        inline void glLoadMatrix(const double* mat)
        {
            GLfloat flt_mat[16];
            for(unsigned int i=0;i<16;++i) flt_mat[i] = mat[i];
            glLoadMatrixf(flt_mat);
        }

        inline void glMultMatrix(const double* mat)
        {
            GLfloat flt_mat[16];
            for(unsigned int i=0;i<16;++i) flt_mat[i] = mat[i];
            glMultMatrixf(flt_mat);
        }

    #else
        inline void glLoadMatrix(const double* mat) { glLoadMatrixd(static_cast<const GLdouble*>(mat)); }
        inline void glMultMatrix(const double* mat) { glMultMatrixd(static_cast<const GLdouble*>(mat)); }
    #endif
#endif

// add defines for OpenGL targets that don't define them, just to ease compatibility across targets
#ifndef GL_DOUBLE
    #define GL_DOUBLE 0x140A
    typedef double GLdouble;
#endif

#ifndef GL_INT
    #define GL_INT 0x1404
#endif

#ifndef GL_UNSIGNED_INT
    #define GL_UNSIGNED_INT 0x1405
#endif

#ifndef GL_NONE
    // OpenGL ES1 doesn't provide GL_NONE
    #define GL_NONE 0x0
#endif

#if defined(OSG_GLES1_AVAILABLE) || defined(OSG_GLES2_AVAILABLE) || defined(OSG_GL3_AVAILABLE)
    #define GL_POLYGON                         0x0009
    #define GL_QUADS                           0x0007
    #define GL_QUAD_STRIP                      0x0008
#endif

#if defined(OSG_GL3_AVAILABLE)
    #define GL_LUMINANCE                      0x1909
    #define GL_LUMINANCE_ALPHA                0x190A
#endif

#ifdef OSG_GL1_AVAILABLE
    #define OSG_GL1_FEATURES 1
#else 
    #define OSG_GL1_FEATURES 0
#endif

#ifdef OSG_GL2_AVAILABLE
    #define OSG_GL2_FEATURES 1
#else 
    #define OSG_GL2_FEATURES 0
#endif

#ifdef OSG_GL3_AVAILABLE
    #define OSG_GL3_FEATURES 1
#else 
    #define OSG_GL3_FEATURES 0
#endif

#ifdef OSG_GLES1_AVAILABLE
    #define OSG_GLES1_FEATURES 1
#else 
    #define OSG_GLES1_FEATURES 0
#endif

#ifdef OSG_GLES2_AVAILABLE
    #define OSG_GLES2_FEATURES 1
#else 
    #define OSG_GLES2_FEATURES 0
#endif


#endif  // __osgGL_h
